Table of Contents
Advertisement
6.
USB Compliance test
S2R72A21 does not belong to Host, Device or Hub within the USB portfolio. This means S2R72A21 does not
have any function for USB compliance testing (Host function, Device function and Hub function). Furthermore,
S2R72A21 does not have any register to maintain VID/PID. Therefore, S2R72A21 itself cannot be USB certified.
Based on the explanation of this chapter, please obtain USB certification for the Host including S2R72A21
through the compliance test as Host.
6.1
S2R72A21 function aimed at USB compliance test
HS Test Packet which is used for the Compliance test is re-synchronized during the S2R72A21 HS operation and
transfer INT→EXT or EXT→INT.
Also it has a feature to transmit the High-speed J/K to the other port, when HS Test J/ Test K are detected from
one port. Please set "0" to either ENABLE pin or XRESET pin of S2R72A21 to recover from this condition.
With these specific features, USB compliance test can be done with combing the general Host.
6.2
General Test method
6.2.1
High-speed Signal Quality
This is the explanation of HS eye pattern acquisition method. In order to acquire the HS eye pattern, it is required
to set the S2R72A21 to HS state (HS synchronizer = ON).
1.
Please connect the HS Host to the INT port and HS Device to the EXT port and confirm whether the Host
and Device is HS connected. After the connection, Please avoid the Bus to be Suspend or FS/LS condition
after connection. Herewith the S2R72A21 would be HS state.
HS Host
2.
Please make the Host output the Test Packet and input towards the INT port. The Host must output the Test
Packet continuously with an appropriate interval in accordance with the USB specification, so that the Bus
would not be Suspend condition. By doing this the S2R72A21 would re-synchronize the Test Packet from
the INT port and output to the EXT port.
3.
Please replace the HS Device of the EXT port to Host Test Fixture.
S2R72A21 Application Note
(Rev.1.00)
S2R72A21
HS
connect
INT_DP
INT_DM
Figure 6.2.1.1
Procedure-1 connection
Seiko Epson Corporation
HS
connect
EXT_DP
EXT_DM
HS USB memory
21
Advertisement
Table of Contents
